package com._101aiot.web.handler;

import com._101aiot.common.resultutil.CommonResult;
import com._101aiot.web.annotation.ResponseResult;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import javax.servlet.http.HttpServletRequest;

/**
 * 重写返回体
 *
 * @author yang
 * @link https://www.cnblogs.com/javayanglei/p/14182703.html
 */
@Slf4j
@ControllerAdvice
public class ResponseResultHandler implements ResponseBodyAdvice<Object> {
    /**
     * 标记名称
     */
    public static final String RESPONSE_RESULT_ANN = "RESPONSE-RESULT-ANN";

    /**
     * 是否请求 包含了 包装注解标记
     * ，没有就直接返回，不需要重写返回体
     *
     * @param returnType    returnType
     * @param converterType converterType
     * @return boolean
     */
    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        log.debug("进入 supports 方法");
        final ServletRequestAttributes sra = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        assert sra != null;
        final HttpServletRequest request = sra.getRequest();
        // 判断请求是否有包装标记
        final ResponseResult responseResultAnn = (ResponseResult) request.getAttribute(RESPONSE_RESULT_ANN);
        return responseResultAnn != null;
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        log.debug("进入 返回体，重写格式 ，处理中！！！body {}", body);

        if (body instanceof CommonResult) {
            // 是 Result 包转好的，说明是处理过异常的，直接返回
            return body;
        } else if(body instanceof String){
            // return 类型 String 的不自动包装
            return body;
        } else {
            return CommonResult.success(body);
        }

    }


}